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Abstract:

Method of stabilizing drinks which is characterized in that A) the
drink is admixed with limonene or limonene-containing formulations and B)
subsequently dialkyl dicarbonate, in particular dimethyl dicarbonate, is
added to the drink.

Claims:

1. Method of stabilizing drinks which is characterized in that A) the
drink is admixed with limonene or limonene-containing formulations and B)
subsequently dialkyl dicarbonate, in particular dimethyl dicarbonate, is
added to the drink.

2. Method according to claim 1, characterized in that the
limonene-containing formulation additionally contains beeswax.

3. Method according to claims 1 and 2, characterized in that drinks
containing sorbic acid are stabilized against microbial infection.

4. Method according to claim 1, characterized in that limonene is used in
an amount from 10 to 5000 ppm.

Description:

[0001] The invention relates to a novel method of preserving drinks.

[0002] There is currently a trend towards natural foods, that is consumers
prefer foods without artificial additives. In the case of drinks,
preserving additives or methods are generally required for packaging.
Currently there are a great number of possible stabilizing means, but
these are in need of improvement in their effect. These frequently
synthetic additives must also sometimes be declared, which is associated
at least with a marketing disadvantage of such drinks.

[0003] Dialkyl dicarbonates are used in the drinks industry for cold
sterilization of non-alcoholic carbonated or still fruit juice drinks,
fruit juices, wines, non-alcoholic wines, ciders, ice teas and other
drinks. This technology for drink stabilization has a number of
advantages. The outstanding advantage here is due to the fact that
flavour and colour are not affected, in contrast to hot packaging. Also,
compared with persistent preservatives such as benzoate and/or benzoic
acid or sorbate and/or sorbic acid there is the advantage, in particular,
of the absence of any flavour impairment. Compared with cold aseptic
packaging, the very significantly lower capital costs in equipment
technology are particularly known as an advantage in the use of dialkyl
dicarbonates.

[0004] The class of substances of dialkyl dicarbonates has the particular
property of hydrolysing, in contact with appropriate (aqueous) drinks,
into the derived alcohols and carbon dioxide. For this reason, an
appropriately treated drink, at the time point of consumption, no longer
has a preservative in the actual sense, i.e. the drinks, after they are
opened, are susceptible to microbiological infection. It is therefore
rather a technical aid, not an additive, for which reason in many
countries the use of dialkyl dicarbonates, moreover, need not be declared
on the label of the drink.

[0005] The object of the present invention is then to improve further the
stabilizing properties during packaging of drinks. Surprisingly, a method
has now been found using which it is possible to improve further the
stabilizing effect of dialkyl dicarbonates.

[0006] A novel method has now been found for stabilizing drinks which is
characterized in that [0007] A) the drink is admixed with limonene or
limonene-containing formulations and [0008] B) subsequently dialkyl
dicarbonate, in particular dimethyl dicarbonate, is added to the drink.

[0009] Limonene can be used, for example as D-limonene (R(+)-limonene), as
L(-)-limonene or as a mixture of the two or as their racemate. D-limonene
(R(+)-limonene is, for example, a component of citrus fruit peels.
Although limonene-containing formulations have already been proposed for
the microbiological stabilization of drinks (U.S. Pat. No. 7,258,883),
these alone have only a very limited effect against many of the
frequently occurring microorganisms which harm drinks and are therefore
of only very limited use for preservation in the packaging operation.
Compared with the prior art, the method has the following advantages:
[0010] A synergistic increase in action of the activities of the
individual components against important microorganisms has been found.
[0011] The method results in total in an increase in the spectrum of
activity, i.e. gaps in activity are unexpectedly closed. [0012] The
method has the advantage that the resultant stabilization of the drinks
behaves in a beneficial manner with respect to time, i.e. short-time and
long-time activity supplement each other. [0013] The method in addition
has the advantage that the drinks, after application of the method, no
longer contain synthetic preservatives. [0014] The sequence of addition
has proved to be important in order to achieve the desired activity.

[0015] Limonene can be used in this method in various forms. Not only
extracts from nature are suitable, but also synthetically obtained
limonene. The use of limonene from citrus peel offers the advantage that
the additional accompanying components of contained terpenes can likewise
contribute an activity. Expediently, the limonene, however, is used as
aqueous limonene emulsion. Co-solvents and/or emulsifiers which can be
used are, preferably, all emulsifiers which are permitted for foods such
as, for example, carrageenan, polysorbate 80, agar, pectin, lecithin,
soya lecithin, Tween® 80, Tween® 60 or Tween® 20 and also
water, aliphatic monoalcohols, in particular C1-C6-alcohols,
such as, for example, ethanol, n-propanol or isopropanol, glycols, in
particular ethylene glycol or diethylene glycol and also dimethyl
sulphoxide (DMSO). Mixtures of these emulsifiers and/or solvents can also
advantageously be used.

[0016] Preferably, limonene is used as a natural extract having a content
of limonene greater than 85% by weight, preferably greater than 90%. This
extract has a fraction of decanal and octanal of together preferably less
than 5% by weight, in particular less than 1% by weight.

[0017] L(-)-limonene can also be used, wherein here, preferably, extracts
of noble firs, or peppermint oils are used. Natural or synthetic racemic
limonene can likewise be used.

[0018] The limonene emulsion preferably used is preferably aqueous and
preferably has a limonene content of 2 to 30% by weight, particularly
preferably 5 to 25% by weight.

[0019] The emulsifiers and/or co-solvents likewise preferably co-used are
preferably co-used in an amount of from 0.05 to 15% by weight, in
particular from 0.5 to 10% by weight, based on the emulsion. Preferably,
as emulsifier, use is made of soya lecithin, carrageenan, polysorbate 80,
agar or pectin, in particular soya lecithin.

[0020] As further additives optionally to be co-used, for example beeswax
and also alkali metal hydroxides and alkaline earth metal hydroxides such
as KOH, NaOH and CaOH come into consideration. Preferably, the further
additives are used in amounts of less than 2% by weight based on the
formulation, in particular on the aqueous emulsion. Beeswax is added
preferably in an amount of 0.01 to 1% by weight.

[0021] The dialkyl dicarbonate used is preferably dimethyl dicarbonate and
preferably has a purity of greater than 99.8%.

[0022] As drinks, in addition to green tea, black tea and also other tea
varieties and tea-based drinks, mention may also be made of carbonated
and non-carbonated non-alcoholic soft drinks, fruit juices, fruit
nectars, wines, non-alcoholic drinks, ciders, iced teas, alcoholic mixed
drinks, flavoured waters or sports drinks. The drinks can preferably also
additionally be preserved with sorbic acid or sorbates. Preferred drinks
contain sorbic acid or sorbate.

[0023] The addition of limonene or formulations of limonene to the drink
preferably proceeds in the mixing tank during mixing of the finished
drink, but addition can also be made to the drinks concentrate which is
to be diluted. Generally, the limonene is added in amounts of 10 to 5000
ppm, preferably 50 to 2000 ppm, in particular 50 to 1000 ppm,
particularly preferably 50 to 500 ppm. The temperatures in this case are
from 0 to 30° C. Addition via metering pumps, as also used for the
addition of flavourings, is likewise possible.

[0024] The addition of dialkyl dicarbonate, in particular DMDC, to the
drink preferably proceeds at temperatures of 0 to 25° C., wherein
amounts of 1 to 250 ppm, based on the drink, in particular 40 to 250 ppm,
are preferred, and are added, in particular, using a metering pump,
directly into the drink stream. A dosage proportional to the drink can be
ensured in this case by a flow meter installed into the drink stream. The
dialkyl dicarbonate is preferably added here, in particular in the course
of 100 hours, preferably 10 hours, in particular in the course of 1 hour
after the addition of limonene.

[0025] The method according to the invention is particularly preferably
used against the following strains: Saccharomyces sp., Lactobacillus sp.,
Acetobacter sp., Penicillium sp., Aspergillus sp., Leuconostoc sp.,
Zygosaccharomyces sp., and others.

EXAMPLES

Example 1

[0026] The activity of the individual components DMDC and limonene (in a
formulation) and the activity of mixtures of DMDC and limonene (in a
formulation) was tested against Saccharomyces cerevisiae.

[0028] LF was added first and then DMDC. Subsequently thereto the mixtures
were thoroughly shaken and incubated at 26° C. for one week. The
cell count present was then determined. The results may be found in Table
1.

[0032] The activity of DMDC against Lactobacillus brevis was compared with
that of limonene. Whereas the activity of DMDC is generally directed in a
broad manner against many microorganisms, here the spectrum of activity
is supplemented very well with limonene.

[0033] Table 2 gives the results of the microbiological colony count
determination. For this a sterilized drink matrix (apple juice/water 1:1)
was inoculated with different cell inocula of L. brevis admixed with DMDC
or limonene in the stated concentrations, the samples were shaken well
and after 24 hours on suitable agar plates the respective cell counts
present were determined (in each case in duplicate).

[0034] "Limonene emulsified" is a solution of synthetic R(+)-limonene (10%
by weight) and soya lecithin (2% by weight) in water. Before use this
mixture is freshly emulsified by means of mechanical shearing.

[0036] An orange juice drink (approximately 20% orange juice,
approximately 8 Brix) without sorbate additions was first admixed with
500 ppm of an emulsified mixture of water 80.9 w/w %, R(+)-limonene from
citrus peel 10.2%, ethanol 6.7% and soya lecithin 2.0% and subsequently
(during the course of 5 hours) admixed with 200 ppm of DMDC. Thereafter
the drink was packaged directly on a drinks bottling line (10 000 l/h)
into 0.5 l PET bottles.

[0037] In this case the limonene-containing mixture was added during final
mixing of the drink, whereas for metering DMDC, an electromagnetic
metering pump connected upstream of the filler was used.

[0038] As comparative experiment, the same drink was packaged
non-preserved, or packaged treated only with DMDC or treated only with
limonene.

[0039] The samples were thereafter regularly inspected visually and
organoleptically.

[0040] Results: The microbiological keeping times of the samples are
listed. [0041] (a) Preserved with DMDC and limonene: >100 days
[0042] (b) Non-preserved: approximately 2 days [0043] (c) Preserved with
DMDC: approximately 20 days [0044] (d) Preserved with limonene:
approximately 2 days

[0046] In this case the limonene-containing mixture was added during final
mixing of the drink, whereas for metering DMDC, an electromagnetic
metering pump connected upstream of the filler was used.

[0047] As comparative experiment, the same drink was packaged
non-preserved, or packaged treated only with DMDC or only with limonene.

[0048] The samples were thereafter regularly inspected visually and
organoleptically.

[0049] Results: The microbiological keeping times of the samples are
listed. [0050] (e) Preserved with sorbic acid, DMDC and limonene:
>100 days [0051] (f) Only with sorbic acid: approximately 6 days
[0052] (g) Preserved with sorbic acid and DMDC: >100 days [0053] (h)
Preserved with sorbic acid and limonene: approximately 5 days